Volume 8, Number 8—August 2002
Research
West Nile Virus Outbreak in Horses, Southern France, 2000: Results of a Serosurvey
Table 3
Immunoglobulin G anti-West Nile virus individual-level prevalence in equines by group size, Camargue, France, 2000a
Group size | Total | Positive (%) | Prevalence Ratio | 95% CI |
---|---|---|---|---|
1–2 animals | 1,353 | 165 (12.2) | 2.2 | 1.6 to 3.0 |
3–6 animals | 1,118 | 114 (10.2) | 1.8 | 1.3 to 2.5 |
7–25 animals | 1,355 | 87 (6.4) | 1.1 | 0.8 to 1.5 |
>25 animals | 1,281 | 55 (5.1) | Ref. | |
Total | 5,107 | 432 (9.7) |
a Chi square = 54.11 (3 degrees of freedom), p<0.0001; 95% CI = 95% confidence intervals.